I am doing a halfwidth radiator, however I am putting the radiator on the passenger's side and would like to use the condenser fan as the primary cooling fan. I will be eliminating the main cooling fan and want to use the PWM output and the control module from the main fan on the condenser fan. I plan on simply rewiring the condenser fan to plug into the module.

The condenser has two fan windings, I have not yet measured the resistance across the terminals. I will do so in the next few days. Other then a potential mismatch in resistance, is there any other issue with doing this? I'll likely be using the high speed terminal.

Here is the diagram for the main fan:


Here is the diagram for the condenser fan:

 

Main fan resistance meeasured as 0.2 OHM on my hand-held (nulling out lead resistance).
AC Fan showed 2.2 OHM on one winding and 14.2 OHM on the other.

I'm guessing the A/C fan is going to have considerably less power to move air. Could be interesting, might have to pick up a SPAL.

 

How about mounting the main fan on the A/C fan frame, and reversing the wiring to the fan?

 

Great idea, so I thought I'd look at it more.

The motor doesn't fit into the A/C fan frame. However, it was only a matter of cutting a little plastic to make it fit. I'll have to build up some of the frame with epoxy so i can screw through the motor mount and into the frame. No big deal there.

Next up though is the blade design. The blades are directional and meant to rotate only one direction. The A/C fan is 5 blades and will bolt onto the main fan motor. The main fan has 9 blades and has considerably thicker blades than the A/C fan. The lead and trailing edge angles of the fan blades are considerably different too and then the curvature is different.

Options:
1: Use the A/C blades and hope the extra power doesn't break it and if it doesn't break it, hope it moves lots of air.
2. Heat up the main fan blades and reshape for the more proper curvature and edge angles
3. Find out whom makes the fan and see if I can get a pusherr style blade.

 

Do you absolutely have to use the PWM feature? The condenser fan will run with or without the a/c being on.

 

I don't have to have it, but I would prefer to have it.

As an update though, I grabbed the propane torch and remolded the blades from the main fan to have a more appropriate blade curvature and tip angles for a pusher application. Worked out better then I expected, although I did break the tip of one blade when I first tried to use a heat gun as it didn't get it hot enough.

The blades aren't exactly what you would want for a pusher setup but they are better then before and it is worth a shot. All told, the change should drop another 20 pounds off the car between the smaller radiator, eliminating one fan, and reducing coolant system volume. If the modded fan doesn't work, I can always try using the A/C fan blade or the stock A/C fan.